The accepted wisdom before this weekend was that one win by Ulster would be the limit of our Heineken Cup ambitions. Connacht and Munster by dint of massive courage and commitment gained unlikely victories, but Leinster in defeat were magnificent and, like the other provinces, this competition makes them draw on new levels of intensity.
Nothing this season prepared us for the performance in Clermont. Leinster for 80 minutes played with a belief that they could win on a ground that is more impregnable than Thomond Park has ever been.
O'Brien, nominally at openside, delivered the perfect defensive game and never missed a tackle. He made a mockery of his long lay-off.
Heaslip, ever the enigma, backed him up to the hilt. Perhaps we expect too much of the No 8, and comparisons with others may not be apposite. His enormous talent led one to believe that he would develop into a marauding back-row. Instead, perhaps the player has belatedly realised his limitations and become a world-class work horse. His control at the base of the scrum was also exemplary.
This was a bad weekend for the line-out and yesterday, both teams had difficulty finding the target.
Leinster's mis-throws were more expensive as they happened at crucial times and in important places. Even at home next week, Leinster will need to be more accurate because a bonus point for the French should be enough to ensure them group success.
Declan Kidney's selection methods were again under the spotlight as Ian Madigan had a magnificent game in attack for Leinster. He may not be Rob Kearney under the high ball but he runs vastly superior angles, one of which could have led to a try and possible victory.
Two other selection choices were spot on. Isaac Boss was strong at scrum-half, but equally importantly he box-kicked with precision. He was the perfect choice for this kind of physical game.
In the centre, Andrew Goodman gave his all and looks the ideal No 12. He overcame an early missed tackle to deliver a crucial role.
The orchestration by Sexton was well-nigh perfect and his kicking game was accurate. He tried two long-shot kicks to the far wing which could have come off, but one wondered if keeping the ball in hand was maybe a better option. Clermont, unlike many French clubs, were alive to that kicking game. In fact, one sensed that the two coaches knew each other too well.
Leinster's 17-match winning streak came to an end but they performed like champions. There is still a mountain to climb and even if the best possible result is achieved next week, based on Exeter's performance in Llanelli a banana skin could yet await.
The Irish provinces demonstrated that they are the cornerstone of this competition. It would be impossible to pick the best performance. Leinster's titanic effort in Clermont may well earn the palm even though they lost.
That said, the English clubs were awful, Northampton conceding four tries at home and Saracens abysmal at the line-out and without a kicking game. How do you explain one of the giants of the French game, Biarritz, losing to the weakest province in Ireland, one that struggles on a weekly basis in the Pro12?
Simply said, the Irish provinces displayed heart and courage in abundance, allied to no little skill.
The problem for the ERC is that they have a competition in which the Italians are not good enough and the Scots not much better. That is the nub of the Anglo-French argument, but their teams in the main show little interest.
In the mid-90s people like Shane O'Mahony at Galwegians and Frank Hogan at Garryowen saw superclubs formed by amalgamations as the future for European competition.
Nobody believed that provinces would be acceptable to the other countries. The competition now has in effect international teams from Ireland competing against clubs from Europe.
Three Irish clubs in the quarter-finals is now a distinct possibility, which will fuel English paranoia. Only Ireland and France are filling stadia for this competition and it faces a challenge, whether or not the dissenters agree to continue.
This weekend was one of the best in Heineken Cup history and an antidote to the economic doom and gloom. Roll on next weekend.